While morality-based exclusions have long existed in patent law as a mechanism to prevent protection of inventions considered contrary to public policy or ethical principles, they have historically played only a limited role in practice. That position changed in recent decades with advances in biotechnology, particularly in stem cells and gene editing, which have brought patent law into direct contact with questions such as the use of human embryos, modification of genetic identity and the acceptable treatment of animals.
As a result, morality and ethical exclusions have moved from largely theoretical concepts to a practical issue that can determine the fate of a patent application.
In this area, the divergence between Europe and the United States is particularly pronounced. Applications prepared with a purely US perspective in mind can encounter unexpected difficulties when examined in Europe, especially where ethical considerations are not addressed in the drafting. This can have a significant impact on IP protection for applicants working in biotechnology and, in particular, gene editing.
US vs Europe: Diverging approaches to gene editing ethical exclusions
The modern US system developed over time to become close to ethically neutral. Early case law (Lowell v. Lewis, 1817) recognised a limited morality filter through “moral utility”, which suggested that inventions should not be “injurious to the well-being, good policy, or sound morals of society”. However, this doctrine gradually fell into decline as the Patent Act of 1952 reinforced a purely technical approach to patentability. This direction was reinforced by later decisions, which confirmed that even living organisms can constitute patentable subject matter (Diamond v. Chakrabarty, 1980) and that immorality is not a basis for refusing a patent (Juicy Whip v. Orange Bang, 1999).
Today, morality plays no meaningful role in US patent examination. The only remaining statutory limitation is the exclusion, introduced by the America Invents Act, of inventions “directed to or encompassing a human organism”. In practice, this is narrow and does not affect most biotechnology inventions, including gene editing techniques. Ethical concerns are addressed through regulation and public policy rather than patentability.
Europe has followed a different trajectory. Article 53(a) EPC has, from the outset, excluded inventions whose exploitation would be contrary to “ordre public or morality”. This principle has been developed through extensive EPO case law, as well as by incorporating the Biotechnology Directive (Directive 98/44/EC) and CJEU case law through the introduction and interpretation of Rule 28 EPC.
The result is a system in which morality is assessed as part of patentability itself. The following examples illustrate how this operates in practice.
Stem cells
The clearest and most developed example of morality-based exclusion in Europe concerns embryonic stem cells.
The most significant decision in defining the patentability of stem cell inventions was the Enlarged Board of Appeal decision G 2/06 (WARF), which established that inventions are excluded if they necessarily involve the destruction of human embryos. This principle was reinforced at the EU level in Brüstle v. Greenpeace, where the CJEU interpreted the concept of a “human embryo” broadly and confirmed that the exclusion applies even where the use of embryos is not explicitly claimed. This approach was subsequently incorporated into EPO practice through the interpretation of Rule 28 EPC.
A key feature of this line of case law is that the assessment is made at the filing date. It is sufficient that, at that time, the invention could only be carried out using embryonic material obtained through embryo destruction. Historically, this meant that even downstream inventions, such as uses of established stem cell lines, could fall within the exclusion. In practice, this issue now arises less frequently, as alternative sources of pluripotent cells have become standard and applications rarely depend exclusively on embryonic material.
Under current EPO practice, the boundaries are defined such that entities lacking the inherent capacity to develop into a human being are not treated as embryos, meaning that alternative technologies such as parthenotes and induced pluripotent stem cells (iPSCs) provide a clear route to patent protection by avoiding the use of embryos entirely.
Gene editing in humans
The development of gene-editing tools, such as CRISPR, has made targeted genetic modification widely accessible, raising immediate concerns about its potential use in humans.
Rule 28 EPC addresses this directly, excluding processes for modifying the germ-line genetic identity of human beings. In addition, the EPO has relied on broader concepts such as human dignity when assessing more complex technologies under Article 53(a) EPC. In T 1553/22, the Board of Appeal refused claims directed to human–animal chimaeras as being contrary to human dignity, in particular because the claims did not exclude the possibility that human cells could integrate into the brain or germ line of the animal.
This illustrates that the assessment is not confined to formal categories but can extend to the underlying ethical implications of the invention, and that the way in which gene-editing inventions are framed can influence how they are assessed. Broad formulations that could encompass germline modification or ethically sensitive uses may attract closer scrutiny, even where the intended application is more limited.
Gene editing in non-human animals
European patent law adopts a more nuanced approach to gene editing in animals. Such inventions are not excluded as such but are subject to a balancing assessment.
Rule 28 EPC provides that inventions are excluded where animals are likely to suffer and where there is no corresponding substantial medical benefit. This approach was developed primarily through the Oncomouse decisions, beginning with T 19/90 and further refined in T 315/03, where the EPO weighed the suffering of the genetically modified animals against the potential benefits of cancer research.
This balancing test recognises that some level of animal suffering is acceptable where justified by a significant medical or scientific benefit. At the same time, it emphasises the need to demonstrate that such a benefit exists in a concrete and credible form across the scope of the claims. It is thus not sufficient to show that examples provide a benefit; rather, the applicant must demonstrate that essentially all embodiments falling within the claims and involving animals likely to suffer are associated with a corresponding medical benefit.
The way in which the technical contribution is described can thus influence the assessment, particularly where the role of the invention in advancing medical research or therapeutic development is clearly articulated. Moreover, in view of the EPO’s strict approach to added subject matter, the specification should explicitly disclose all embodiments for which a medical benefit can be demonstrated, even where these could be considered obvious.
Conclusion
The contrast between Europe and the United States reflects two fundamentally different views of the role of patent law.
In the United States, morality has effectively been removed from the patentability analysis. Patent law focuses on technical innovation, while ethical questions are addressed elsewhere. In Europe, morality remains embedded within the patent system. Through Article 53(a) EPC, Rule 28 EPC and their interpretation in case law, the EPO applies an ethical filter during examination.
For applicants working internationally, this difference has practical consequences, as decisions taken during drafting, particularly in fast-moving areas such as biotechnology, can influence whether an invention falls within or outside the scope of these exclusions in Europe.
